Input is pink shaft having an eccentric.
Red cutter creates profile on yellow work that is fixed to grey gear shaft. Transmission ratio from pink pulley to the grey gear shaft is 6 so the created profile of star shape has 6 wings. The wing is not symmetric because the grey gear shaft rotates irregularly.
The profile shape also depends on relative position between the cutter and the work.
The black belt represents tooth belt. Using chain drive instead of belt one is better.